In the observational study, the data provides a correlation between living close to the ozone hole and increasing one's chance of developing skin cancer. In the experimental study, where variables are directly manipulated and controlled, a relationship between exposure to higher levels of UV-B and contracting skin cancer is tested in mice.

CAUSE AND EFFECT

Explanation:

Cause and Effect is a relationship that is observed between two variables.

Cause is known as a independent variable while Effect is a dependent variable.

Cause is defined as a thing that allows a situation or incident to happen while,

Effect is defined as the aftermath or the evidence or impact of what has happened.

In the above question, the Cause( Independent variable) is known as the exposure of the skin to UV-B while the contracting of skin cancer is known as the Effect( dependent variable).

succession returns a disturbed

ecosystem to a more stable state. this is also classified into two (2) types:

primary succession and secondary succession. the primary succession arises when

a new land is transformed and a bare rock has been exposed providing an environment

that can be occupied for the first time. while, secondary succession occurs

when a previously occupied environment was disturbed that kills much of all its

community

explanation: